Stigma croci

Chromatography of flower pigments (anthocyanins) is performed on both. silica gel and cellulose plates. Silica gel plates are used for TLC of Croci stigma extracts. 

Antiiocyamns show red to blue-violet, Croci stigma constituentvS yellow colour (vis). Anisaldehyde-sulphunc acid reagent (AS No. 3)... 

Croci stigma (5) is characterized by yellow-coloured crocin and crocetin (Rf 0.15-0.25) in vis. Both show fluorescence-qiiendiing in UV-254nm, as well as picrocrocine (R, 0.55), and become dark violet-blue with AS reagent (vis). Weak zones in the R, range of Sudan red (6), e.g. 4-hydroxy-cydocitral or safranal can be present. 

Monograph, Croci stigma, Bundesan-zeiger, no. 76 (April 23, 1987). 

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